2 cases here:
- at home, I can use operamail to fetch email from... let's say gmail's IMAP server
- at work, I'm behind a proxy, and when I tried to use operamail to fetch emails, it failed with the generic message 'The connection with the IMAP server was unexpectedly interrupted.'

2 Answers
2

Opera Mail normally uses the same proxy as defined in preferences, for the whole program.

Fact is, in some firms, only some ports are available through the proxy. If you can't use the imap port (you can try with another mail client program, like Thunderbird), then it won't work either in Opera Mail.